The present invention relates to a simulator and simulation method for use in the training of surgeons for image-guided surgical procedures.
In an image-guided surgical procedure, the surgeon manipulates a surgical probe such as a catheter, trocar, endoscope or other instrument within the body of a living subject such as a human or other mammal while the subject is being imaged using a modality such as magnetic resonance imaging (xe2x80x9cMRIxe2x80x9d), fluoroscopic imaging or computerized axial tomography (xe2x80x9cCATxe2x80x9d). Image-guided surgery can be performed as a minimally-invasive procedure, in which some or all of the probe typically is hidden within the body, so that the surgeon cannot see the operative portion of the probe directly. The imaging device displays a representation of the probe in conjunction with the image of the subject""s body, so that the surgeon can determine the position and orientation of the probe relative to the internal organs of the subject by observing the image. In some cases, the representation of the probe is created by the imaging instrument in the course of imaging the subject. For example, where a radioopaque probe is used in conjunction with fluoroscopic imaging, the probe will appear as a part of the image. In other cases, the position and orientation of the probe relative to the imagining instrument is monitored by a separate monitoring system, and a computer-synthesized representation of the probe is combined with the image data to form a composite image having the representation of the probe in the correct position and orientation. For example, Dumoulin et al., U.S. Pat. No. 5,211,165 discloses a system in which the position of a probe is monitored by an radio-frequency (xe2x80x9cRFxe2x80x9d) tracking system while an image of the subject is acquired by MRI, and a representation of the probe is superimposed on the MRI image.
Presently, the training of surgeons for surgical procedures takes many forms including the use of cadavers and mannequins. Training exercises using a cadaver or a mannequin by itself do not provide realistic training for the surgeon so as to help him or her visualize the position of a probe in the patient based on the images displayed by an imaging system. It is normally impractical to conduct cadaver or mannequin training using the real imaging system which will be used in actual surgery, due to considerations such as the cost and limited availability of the real imaging system. Although computer simulations have been proposed, these typically do not provide the physical sensations associated with actual manipulation of a surgical probe.
Thus, there have been needs for improved simulation apparatus and simulation methods.
One aspect of the present invention relates to a simulator for use in the training of surgeons. The simulator utilizes information defining the position of a surgical tool or probe used by the surgeon trainee relative to a mannequin.
A simulator according to this aspect of the invention desirably includes a mannequin corresponding to a living mammalian subject such as a human or non-human mammal. The mannequin desirably includes model internal organs within it. The simulator also includes a surgical probe and means for providing position and orientation information defining the position and orientation of the surgical probe relative to the mannequin. A memory device stores image data defining an image representative of internal organs found within the living subject corresponding to the mannequin. The simulator desirably further includes means for providing a composite image including images of internal organs and a representation of the surgical probe based on said image data and said position and orientation data. The composite image providing means desirably is arranged so that in the composite image, the position and orientation of the representation of the probe relative to the images of the internal organs correspond to the position and orientation of the probe relative to the internal organs of the mammalian subject which would be observed in a real image of the mammalian subject with the surgical probe at a position and orientation relative to the living subject corresponding to the position and orientation of the probe relative to the mannequin.
Further aspects of the invention provide methods of simulating an image-guided surgical procedure using a mannequin and a composite image as discussed above in connection with the simulator.
The simulator provides a realistic training experience. As the trainee surgeon manipulates the probe, he or she sees the representation of the probe move on the displayed composite image in the same manner as he would see the representation of a probe move on the image in a real image-guided surgical procedure. At the same time, the trainee receives the physical, tactile experience associated with moving the probe through the spaces defined by the internal organs.
The probe position and determining means use of a series of light beams placed inside the mannequin in a gridlike pattern. Alternatively, magnetic, electromagnetic and optical position determining systems may be employed.